Cavity Insulation between Joists

[murphyabu]

Evening all,
Making some progress on our extension and I'm trying to save some money (while not compromising) on insulation etc.

I've found a plentiful supply of HP Rockwool Partial Fill insulation which is reasonably priced, but I want to know if it can be used between first floor joists for acoustic insulation.

Has anyone done similar?

Thanks

 

[cdbe]

I'm the opposite, maybe we should swap! I found some cheap Rockwool acoustic insulation and used it to insulate under my floors - there's usually plenty of performance data available - mine performed slightly less well thermally so I upped the thickness, you probably need to do the same.

 

[murphyabu]

I'm the opposite, maybe we should swap! I found some cheap Rockwool acoustic insulation and used it to insulate under my floors - there's usually plenty of performance data available - mine performed slightly less well thermally so I upped the thickness, you probably need to do the same.

Maybe naively I'm not bothered about thermal performance, as the joists are effectively an internal partition (i.e. it's within the thermal envelope of the house). But, I do want to maximise on acoustic insulation between the ground/first floor.......